The driving forces for this proposal are the ever increasing number of genes that have been sequenced and whose protein products have been expressed in quantities sufficient for biophysical study of their interactions with other proteins, nucleic acids and ligands and the difficulty in accessing these technologies. We propose, therefore, to initiate a new section within the Keck Foundation Biotechnology Resource Laboratory (KFBRL) that will bring state-of-the-art biophysical technologies suitable for detecting and quantifying macromolecular interactions to hundreds of Yale and non-Yale users of the KFBRL so these investigators may transcend the primary sequences that are increasingly yielding to genome projects and more rapidly and fully answer the more interesting questions pertaining, for instance, to how the approximately 80,000 human proteins accomplish their functions. To begin this task we are requesting funds for an HPLC SEC/laser light scattering system. In support of this request are research projects from 17 investigators at 6 institutions that do not have access to the proven ability of this instrumentation to detect and quantify a wide array of protein: protein, protein: nucleic acid and other biomolecular interactions. The requested instrumentation is needed to advance our knowledge across a broad biochemical and biomedical front that includes but is not limited to developmental regulation, DNA damage recognition, blood pressure recognition., tumorigenesis, signal transduction, pre mRNA biogenesis, immune responses, and molecular mechanisms of exo and endocytosis. The strengths of this proposal include the extremely wide, diverse and productive user base that supports the KFBRL; the demonstrated ability of the KFBRL to bring biotechnology to bear on the hundreds of difficult research problems. That confront these users; the complementarity between the biophysical instrumentation requested and the instrumentation in the KFBRL; the technical and organization expertise to bring the requested instrumentation immediately "on-line" and to keep it operating optimally and continuously far into the future; and the extensive expertise and preliminary results that have been gained with an SEC/LS system that was on loan to the KFBRL for several months. These results demonstrate the potential for the requested instrumentation to make to major contribution to biomedical and biochemical research that will extend to many of the greater than 800 investigators from greater than 200 institutions that currently rely on the KFBRL for state-of-the-art biotechnological analyses and syntheses.